In search of optimal nutrient density: veggies or whole grains?

In previous articles I’ve written about the heath benefits of eating whole grains, which have been shown in large epidemiological studies to be associated with reduced all-cause mortality risk. Based on this data, the USDA’s MyPlate recommends a minimum of 3.5 oz, up to 7 oz. of whole grains on a 2200 calorie diet. 3.5 servings of barley yields 350 calories, whereas 7 oz. yields 700. In terms of percentage of total calories, MyPlate recommends that 16-32% of daily calories should come from whole grains.

In terms of vegetables, MyPlate’s recommendations are shown below. They recommend 3 servings of vegetables per day, with these amounts varied between green vegetables (and other vegetables), red and orange vegetables, beans and peas, and starchy vegetables. For ease of calculation I grouped ‘other vegetables’ with green vegetables. Based on the recommended weekly servings for each group and representative foods, I calculated weekly calorie amounts for each group. Average veggie calories per day = 187. Divided by 2200 calories, that equals 8.5% of total calories.

myplate

So clearly MyPlate wants us to eat between 2-4 fold more whole grains than veggies, in terms of total daily calories, but why is that? In a meta-analysis of 7 studies including 660,186 subjects, increased vegetable consumption is also associated with reduced mortality risk, as shown below:

veg mortality

Maybe whole grains are superior to veggies in terms of nutrient density? To see if that’s true, in the Table below I compared the nutrient composition of broccoli, spinach and romaine lettuce against barley (the king of grains for fiber), whole wheat spaghetti and oats. How do they compare in terms of macronutrients, when each has 100 calories? First, it should be obvious that to get 100 calories of veggies (see the serving column), you will eat significantly more food. To most, this will seem like a bad thing. But more chewing for the same amount of calories may end up in eating less, an important fact because of the worldwide explosion in obesity rates. Second, each of these veggies have 2-3 fold more protein and 3-4 fold more fiber than than whole grains. So far, veggies are far superior to whole grains.

vegc1

What about vitamin content? As shown below, veggies crush whole grains for vitamin content. Whole grains are not better than veggies in terms of vitamin content for any category.

vegc vitamins

Maybe mineral content is better in whole grains? As shown below, they’re not. Veggies are much better in 9/10 mineral categories, with whole grains having marginally more selenium than veggies.

vegc miner

Based on these data, I have now dramatically increased my daily vegetable intake, while reducing my whole grain intake. Shown below is a snapshot of today’s veggie (and some other foods, too) intake, and it’s also important to mention that this amount is now representative of my daily vegetable intake. I haven’t eliminated whole grains, only minimized them.

veggies cal

My total veggie intake between carrots, beets, green peas, corn, asparagus and 1 pickle spear is 50.6 oz, or 1416 grams. Considering that 1 serving of vegetables = 80g, I ate 17.7 servings of veggies today. That amount is almost equal to what MyPlate recommends to eat in 1 week!

If you’re interested, please have a look at my book!

References:

Nutrition data from ndb.nal.usda.gov

Wang X, Ouyang Y, Liu J, Zhu M, Zhao G, Bao W, Hu FB. Fruit and vegetable consumption and mortality from all causescardiovascular disease, and cancersystematic review and dose-response meta-analysis of prospective cohort studiesBMJ. 2014 Jul 29;349:g4490.

Dietary fiber from whole grains is associated with reduced mortality risk-which grains are highest in fiber?

In an earlier post I reported that dietary fiber from whole grains is associated with reduced mortality risk for all causes, cardiovascular disease, cancer, respiratory and infectious disease in both men and women (https://michaellustgarten.com/2014/08/02/is-dietary-fiber-associated-with-reduced-mortality/).

More specifically, which whole grains are highest in fiber?

Shown below are grams of dietary fiber per 100 grams (uncooked) for each respective grain.

grain fiber

It should be clear from the table that barley (16.6g) and rye (15.1g) are the all-stars for grains with the highest amounts of dietary fiber per 100g. Wheat (12.2g) and oats (10.6g) are also excellent sources. Because of the association between dietary fiber from grains and reduced mortality risk, it might be a good idea to add these foods to your diet!

If you’re interested, please have a look at my book!

Which grain is the best source for protein, essential amino acids, BCAA and arginine?

Listed below are total protein, essential amino acids, branched chain amino acids, and arginine content for quinoa, oats, corn, millet, barley, brown rice and potato. The values provided are for 100 calories, for each respective grain.

Let’s ask some questions:

1. Is there a difference in protein content among these 7 grains?

Yes, there is a difference. Per 100 calories, oats are king, containing more than 2x the amount of protein in barley, the lowest ranking grain on this list. In fact, oats, quinoa and corn each have approximately 2x more total protein than each of the lowest ranking grains, potato, brown rice and barley. Millet is intermediate, at 2.95 grams of protein per 100 calories.

Table 1 Grains

2. Can these grains be considered as “complete protein”?

A “complete protein” is defined as containing all of the 10 essential amino acids (EAA). As shown in the table below, each of the 7 grains contains all of the 10 essential amino acids. Oats contain the greatest amount of essential amino acids (Total EAA), followed by corn and quinoa.

Table 2 Grains

3. Which grain contains the highest amount of branched chain amino acids (leucine, isoleucine and valine)?

The branched chain amino acids (BCAA) leucine, isoleucine and valine are well documented to stimulate muscle protein synthesis (Blomstrand et al. 2006). Oats, corn and millet contain the highest amounts of total BCAA, followed by quinoa, brown rice, potato and barley.

Table 3 Grains

4. Which grain is highest in arginine?

Arginine is the required precursor for the production of nitric oxide (NO), which has been claimed to promote vasodilation in active muscle during exercise, thereby improving strength, power and recovery (Alvares et al. 2011). As shown in the table below, once again, oats contain the highest amount of arginine, followed by quinoa and brown rice.

Table 4 Grains

Conclusions:

1) Oats contain the highest amount of total protein, relative to the other grains on this list.

2) All of the 7 grains on this list contain milligram amount of all of the 10 essential amino acids, making each of them a complete protein. Oats contain the highest total amount of essential amino acids, relative to the other grains on this list.

3) Oats also contain the highest amount of branched chain amino acids and arginine, when compared with all the other grains on this list.

If you’re interested, please have a look at my book!

References:

Álvares TS, Meirelles CM, Bhambhani YN, Paschoalin VM, Gomes PS. L-Arginine as a potential ergogenic aid in healthy subjects. Sports Med. 2011 Mar 1;41(3):233-48.

Blomstrand E, Eliasson J, Karlsson HK,Köhnke R. Branched-chain amino acids activate key enzymes in protein synthesis after physical exercise. J Nutr. 2006 Jan;136(1 Suppl):269S-73S.

Nutritional data provided by http://www.nal.usda.gov/fnic/foodcomp/search/